Paul Nicklen risks life and limbs to take photographs in some of the most inhospitable places on earth. One of them has just won him the prestigious Veolia Environment Wildlife Photographer of the Year award.
It is for a picture he took underwater of emperor penguins bursting through a hole in the ice off Antarctica.
Nicklen says he wants to do more than just shoot pretty pictures. "With the current state of the planet, if we are just shooting pretty pictures, then we're just fiddling while Rome burns," he told the BBC. "We need to be doing conservation-driven stories that educate people."